Choice A is the correct answer. Piecewise logic.

1. First 7 days: $30 \times 7 = 210$.
2. Extra days: $d - 7$.
3. Extra cost: $25(d - 7)$.
4. Total: $210 + 25(d - 7)$.

💡 Strategic Tip: Don't just multiply the new rate by total days ($25d$). You must account for the first bracket separately.

Choice B is incorrect because ignores discount. Choice C is incorrect because applies discount to all days. Choice D is incorrect because double counts days.